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181.
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183.
Yoichi Tanaka Yuji Taniguchi Daisaku Tanaka Masatoshi Toyoda Hideshi Ishii Teruo Tanabe Yasuko Terada Shinjiro Hayakawa Jun Kawai 《Analytical sciences》2005,21(7):839-843
The Kosa (yellow sand) aerosol affects the global environment as well as human health because it migrates from the interior of China to other areas, absorbing various atmospheric elements. Investigation into individual Kosa aerosol particles, which are submicroscopic to several tens of micrometers in diameter, is required to resolving the issue. We installed a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectrometer (EDX) on a synchrotron radiation (SR) beam line and introduced the SR beam into the SEM chamber for combinatorial application of SEM-EDX and SR X-ray fluorescence (SR-XRF) spectrometry to individual particles. It should be noted that detailed topographic observation by SEM and sensitive elemental analysis by SR-XRF, both crucial for individual particle measurement but which previously had to be carried out separately, were jointly performed inside the SEM chamber in this setup. Here, we show that SR-XRF results, in conjunction with SEM images, contributed toward resolving individual particle dispositions. Atmospheric sulfur primarily adheres to calcium in the aerosol particles and the particle surface roughens as a consequence of the chemical reaction between the two elements. 相似文献
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185.
Ayumi Ishii Shinobu Kishi Hideki Ohtsu Toshifumi Iimori Takakazu Nakabayashi Nobuhiro Ohta Naoto Tamai Milan Melnik Miki Hasegawa Yuzo Shigesato 《Chemphyschem》2007,8(9):1345-1351
The electronic and structural behaviour of a Pr(III) complex with 4,7-diphenyl-1,10-phenanthroline, [Pr(bathophen)(2)(NO(3))(3)], is investigated with respect to the effect of configuration changes on the Pr(III) centre. [Pr(bathophen)(2)(NO(3))(3)] luminesces from the excited states of the ligand and the metal ion. The fluorescence, ff-emission ((1)D(2)-->(3)H(4)), and phosphorescence bands appear at 394, 608.2 and 482 nm, respectively, in the solid state. In acetonitrile, the complex also shows multiple emissions. From the time-resolved emission and the lifetime measurements, the excitation energy-transfer in [Pr(bathophen)(2)(NO(3))(3)] is clarified, that is, the upper excited triplet level of the ligand acts as an energy donor, while the (1)D(2) levels of Pr(III) is the acceptor. Additionally, the emission phenomena of the complex can be modified by molecular distortion, particularly by rotation of the phenyl groups in the ligand. 相似文献
186.
187.
Ken Naitoh Yasuo Takagi Kunio Kuwahara Egon Krause Katsuya Ishii 《Fluid Dynamics Research》1990,6(5-6):277-294
The transition to turbulent flow in the compression stage of a reciprocating engine is studied by obtaining the finite-difference numerical solutions to the governing Navier-Stokes equations without using explicit turbulence models. A computational method is developed under the assumption that the flow is in a low-subsonic regime with strong compression. The numerical method is a simple extension of the well known MAC method. Computations were performed for three different chamber geometries at the engine speed of 1400 rpm. The results of the computations clearly demonstrate the transient process in which large tumbling vortices break down into smaller ones near the end of the compression process. The transition process is also caught experimentally by using Mach-Zehnder interferometry. 相似文献
188.
Optical Review - The response of light in a nonlinear dispersive medium is governed by the nonlinear Schrödinger equation (NLSE). In general, for higher order group velocity dispersion (GVD)... 相似文献
189.
Kun‐Heng Chiang Shi‐Han Lu Wan‐Ping Yen Naoto Uramaru Wei‐Siou Tseng Te‐Wei Chang Fung Fuh Wong 《Heteroatom Chemistry》2016,27(4):235-242
A convenient synthetic method for N‐arylformamide derivatives was successfully developed by reacting α‐iodo‐N‐arylacetamides with formamide. This method was applicable to α‐iodo‐N‐arylacetamide substrates bearing electron‐donating or electron‐withdrawing groups, N‐(benzo[d][1,3]dioxol‐5‐yl)‐2‐iodoacetamide, 2‐iodo‐N‐(pyridin‐2‐yl)acetamide, and 2‐iodo‐N‐(naphthalen‐4‐yl)acetamide to give the corresponding N‐arylformamides in moderate to excellent yields (65–94%). A plausible mechanism was proposed to account for the new transformation. 相似文献
190.
Takahiro Matsumoto Seikou Nakamura Naoto Kojima Tomohiro Hasei Masayuki Yamashita Tetsushi Watanabe Hisashi Matsuda 《Tetrahedron letters》2017,58(36):3574-3578
From the methanolic extract of the aerial parts of Isodon japonicus, two new ent-kaurane diterpenes, isodonterpenes I and II, were isolated together with 10 known diterpenes. Their chemical structures were elucidated on the basis of chemical and physicochemical evidence. The absolute configuration of isodonterpene I was elucidated by Cu-Kα X-ray crystallographic analysis. Antimutagenic activities of the major diterpenes were evaluated by the Ames test. This study represents the first evaluation of the antimutagenic activities of ent-kaurane diterpenes. 相似文献